Hawking also answered several pre-submitted questions during his Sydney appearance, including a surprising one about Zayn Malik's departure from pop band One Direction. "Finally, a question about something important," he said. Hawking used the opportunity to share his thoughts on the possibility of multiple universes.

"One day there may well be proof of multiple universes," he said. "It would not be beyond the realms of possibility that somewhere outside of our own universe lies another different universe. And in that universe, Zayn is still in One Direction."